How? his survivability is low he cant tank a lot doesnt deal nor does he heal alot of damage.
Blaze is currently one of the tankiest heroes in the game if you play him correctly, I don’t know where you got your info from because he has insane self-healing
Dont play Blaze as maintank, even Lauber gave up that idea…and i guess you are not Lauber.
However: Blaze is currently (Feb 2022) the strongest Bruiser in game. Selfheal, waveclear, escape everything thas needed for this role he is providing easiely. On top of that slows, stuns and most of all the bunker to help the team in figths. In High lvl organized play he is first pick material.